Re: Readahead value 128K? (was Re: Drastic Slowdown of 'fseek()'
From: Al Boldi
Date: Mon Mar 13 2006 - 06:37:06 EST
Marr wrote:
> The 2.6.13 kernel on ReiserFS (without using
> 'nolargeio=1' as a mount option) still takes about 4m35s to fseek 200,000
> times on that 4MB file, even with 'hdparm -a0 /dev/hda' in effect.
try this magic number:
echo 192 > /sys/block/hda/queue/max_sectors_kb
echo 192 > /sys/block/hda/queue/read_ahead_kb
Anything outside 132-255 affects throughput negatively.
Also, can you dump hdparm -I /dev/hda?
Thanks!
--
Al
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